Changing distributions of the cosmopolitan mosquito species Culex quinquefasciatus Say and endemic Cx. pervigilans Bergroth (Diptera: Culicidae) in New Zealand

ABSTRACT

New Zealand has 13 endemic mosquito species, which are predominantly bird-biters, exhibiting low levels of vector competence, and are adapted to their native ecosystems. Anthropogenic land-use change are well-suited to domesticated exotic species that have already established here. While some endemic species, such as Culex pervigilans, can also be found vutilising such environments, there are indications of population decline and displacement. The cosmopolitan Cx. quinquefasciatus has been established in New Zealand for more than 180 years, and was believed to be confined to the warmer, northern regions. However, biosecurity records of obtained specimens collected by the National Mosquito Surveillance Program, at various points of entry (POE) for goods and international travel, suggest an expansion of this range. Changes in the distributions of Cx. quinquefasciatus and Cx. pervigilans over the last fifteen years in New Zealand, are evaluated herein, with the conclusion that Cx. quinquefasciatus is increasing both in distribution and population density over time, and should be considered an invasive species. Evidence of a southward spread is likely a result of anthropogenic environmental changes particularly favourable to Cx. quinquefasciatus. A trend of considerable ecological and public health importance. Similarly clear effects on urban Cx. pervigilans populations were not observed.

KEYWORDS:

• Invasive species
• mosquitoes
• monitoring
• distribution
• public health
• anthropogenic changes

Acknowledgements

We gratefully acknowledge all Health Protection Officers for diligently conducting the National Mosquito Surveillance in New Zealand. We thank all entomologists at NZ BioSecure Entomology Laboratory for identifying the samples used for this study. Special thanks are addressed to Amy Gault and Rodrigo Salvador for all the valuable contributions to this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was financially supported by the Ministry of Heath – Manatū Hauora of Aotearoa – New Zealand.